Solder bridge
A solder bridge is a connection element made of conductive and solderable material for the conductive connection between two or more connection points on a circuit board . In addition, a solder bridge can also be an unintended electrical connection between two or more electrical networks.
Solder bridge as a connecting element
commitment
The solder bridges are used to save levels for plated-through circuit boards or to create certain default settings for circuits . Solder bridges can also be used to overcome difficulties in disentangling printed circuit boards . On simple circuit boards, solder bridges form ground and voltage lines and can also serve as soldering support points for backup capacitors.
Compared to wires, solder bridges have the advantage of a fixed shape and they can be used like normal components without additional reworking and, above all, they can be assembled by machine.
Alternatives
An alternative to solder bridges in connection technology is, for example, the winding connection .
Another alternative are "zero ohm resistors" , which have the same dimensions and connections as normal resistors and which can be assembled and processed like these.
If solder bridges are used to set functions, miniature switches or jumpers can also be used instead.
Representation in the circuit diagram
The solder bridges are often not shown in circuit diagrams. But they are part of the wiring plan, assembly plans and parts lists.
Solder bridge as a defect
Hand soldering
The same name is also used to describe a defect on circuit boards, the solder bridge. If, during hand soldering, too much solder or, for example, bent component connection wires and their solder wetting, accidentally makes contact with an adjacent conductor track or a soldering pad, this is nothing other than an electrical short circuit . It is important to avoid this by working cleanly during hand soldering and to find and repair it as quickly as possible in the event of a fault.
Wave and selective soldering
Furthermore, there may be solder bridges through the liquid solder during wave soldering. The risk of solder bridges is greater, the smaller the distance between the individual pins. There tend to be hardly any solder bridges in an optimally set wave soldering system with a pin spacing of 2.0 mm or more. With a pin spacing of 1.27 mm, more solder bridges must be expected. In addition, the protrusion of the pin over the circuit board also has an influence on the likelihood of solder bridges. There are more solder bridges with a larger pin protrusion.
The same effects that occur with wave soldering can also be observed with selective soldering.
Reflow soldering
When reflow soldering SMD components , solder bridges can also occur if, for example, two printed deposits of solder paste run into one another. In the case of simpler SMD components, this type of error can usually also be remedied (by hand). With BGA components, this is usually only possible with a complex rework .
literature
- Reinard J. Klein Wassink: Soft soldering in electronics . 2nd Edition. Eugen G. Leuze, Saulgau 1991, ISBN 3-87480-066-0 .
- Wolfgang Scheel (Hrsg.): Assembly technology of electronics . Verlag Technik et al., Berlin et al. 1997, ISBN 3-341-01100-5 .